Before popular children’s author Theodor “Dr. Seuss” Geisel died in 1991, he told his wife, Audrey, that she would be “the one who would have to live with all the critters and move them on.”

That she did, shepherding his legendary menagerie — the Cat in the Hat, the Grinch, Horton, the Lorax — into the 21st century, where it continues to entertain new generations of youngsters.

Geisel died Dec. 19 at her Mount Soledad home. She was 97.

Petite and often understated — her jewelry box at home was an egg-carton painted gold, according to family members — she was a fierce protector of her husband’s creations and legacy, and a major donor to La Jolla institutions he supported and helped to flourish, including UC San Diego.

Born Audrey Stone on Aug. 14, 1921 in Chicago, she grew up in a household jostled by hard times, according to an obituary prepared by the family. Her father was a singer and dancer, and soon disappeared from her life. She grew up living with her mother, or family friends, or, once, in foster care.

At age 21, she entered the nursing program at Indiana University, where she met E. Grey Dimond, a pre-med student who would become her husband. They both worked at Massachusetts General Hospital in Boston before moving to Kansas, where he became the dean of cardiology at the University of Kansas. They had two daughters there.

In 1960, they moved west to La Jolla. Mrs. Geisel caught a glimpse of the ocean. “I saw that,” she often remarked later to family members, “and knew I’d stay here forever.”

The Dimonds eventually traveled in the same social circles as longtime La Jollans Ted Geisel and his first wife, Helen. By 1968, both those marriages had ended, and Ted and Audrey were wed.

After Ted’s death in September 1991 at age 87, the City held a tribute in Balboa Park, where Mrs. Geisel talked about his legacy in a way that foreshadowed her subsequent efforts to protect and promote his work.

“His name never comes up when you’re talking about the underbelly of the world,” she told the Union-Tribune. “It is always used when you’re talking about the good, the best of the world.”

A year later, she donated more than 4,000 items — original drawings and manuscripts, college notebooks, letters — to the library at UCSD, expanding his reach from popular culture into the world of academic research. More donations over the years have created a repository that is a must-visit for scholars looking to understand the author’s creative process and his enduring influence on children’s literature. The collection is housed in the Geisel Library, so named after Mrs. Geisel donated $20 million to it in 1995.

The ongoing popularity of Seuss — his four-dozen books have sold more than 650 million copies worldwide — also created steady interest in film and theater adaptations and related merchandise. Seuss Enterprises, based in La Jolla, was set up to license the use of the characters. Forbes estimated his estate’s earnings over the past year at $16 million, placing him sixth on the magazine’s list of highest-paid dead celebrities, just behind Bob Marley and ahead of Hugh Hefner.